Monthly Archives: April 2008

Digital Photographic Sensors

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In the realm of digital photography there are tons of things that can change the quality of the picture the camera takes. Most of these things take place right within the camera. To start with, if you’ve got a lousy lens, it doesn’t matter if everything else is great because light hitting great stuff will have been ruined before it got there. From the other direction, the same problem can exist. If your sensor sucks, it makes no difference how pristine the image is when it hits it. Besides that, the quality with which the camera plays with the data it gets has a huge bearing on the final output as well. That can mean how well the camera does its ISO noise reduction, how good the JPEG compression algorithm it uses is (or if it’s used at all), methods of analog to digital conversions, and so on.

The two main types of sensors in a digital camera are CCD (Charge-Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor). The differences between the two are huge, and arguments about which is better abound. The basic idea of both is to collect light and spit out a bunch of data in the form of a photograph. The similarities between the two almost stop there.

A CCD typically has a single “drain” point. Through that spot all of the data for the entire picture must be passed. The kicker is how that data ends up in that spot to be drained and the form the data is in when it is drained. Each row of the image actually cascades across the entire sensor into a holding row (which is sometimes the last row in the image itself) and then across that row to a single dot. All this shifting of charge is done as actual voltage signals based on massive input from a battery and signal strength data from each pixel of the image. Also, as voltages are shifted across the sensor, data of previous pixels can remain slightly and end up added into the latest shifted row. This can result in smudging within the picture or famous side effects such as “purple edges.” The advantage is that all data is uniformly interpreted through a single drain which has what I like to call a “single opinion” about how each color looks. The disadvantage is that to access any single pixel the whole sensor must be flushed. When the data leaves the chip it is no where near ready to be stored in an image file destined for a printer or computer as all we have is a stream of voltages. These voltages need to go through conversion chips to handle all the steps of converting them into digital data.

A CMOS sensor on the other hand has a drain for every single pixel in the image. The side effect of this is that there are loads of bits of circuitry for every single pixel. As it turns out, this is ok due to sensor creation processes that are identical to the creation of the processor in your computer. In some cases, each pixel has it’s own amplifier to further complicate what is happening at each pixel. The advantages are that data never needs to be forced across the whole sensor to be drained (effectively eliminating any problems of smudging) and that each pixel can be accessed individually (meaning the whole sensor need not be flushed to access it), and the power consumption is usually on the order of 1/100th of a similar CCD. The disadvantage is that every single pixel in the camera can have its own opinion about how it looks. Meaning, what is blue to one pixel may be a vaguely purple shade to the one next one down the line. This means seriously complex noise reduction must be done to end up with a clean image. The output of a CMOS sensor is data that can almost directly be stored as an image since all of the conversions take place right in the sensor. This also usually means there are very few required supporting chips and you can expect tremendous battery life.

Every camera I’ve ever owned has been a digital one. Every digital camera I’ve owned up until now has been a point and click style with a CCD. My current camera marks my first steps into the world of dSLR (Digital Single Lens Reflex) and my first CMOS sensor. To the uninformed dSLR represents the “professional” grade cameras that are bulky, support interchangeable lenses and have amazingly high price tags. To me it is the flexibility to choose my own optics for each situation. It’s exciting times from the perspective of photographic freedom, but I’m still learning the finer points of how to use the camera. Some would call this user error, but I think it’s actually more along the lines of user perception. With big complicated lenses comes new photo characteristics and that means that in general I’ve found fewer things to be in focus when the picture is taken.

Standard point and click cameras tend to be equipped with a lens that produces pictures with massive depth of field. With better lenses on a dSLR comes control over depth of field. The reality and learning curve required to identify that which is muddy looking and that which is simply out of focus due to not being in the depth of field is part of what I’m coming to terms with now as I adapt to my new photographic potential.

Deer in Headlights

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It all started with an innocent purpose of a late night pizza from a local pizza place. Local out by me means a 6 minute drive through hilly, curvy, back roads with loads of forest and an occasional small farm. A nice little drive for a delicious pizza dinner.

I have always been careful when driving in this area because there are deer everywhere. On my own street there is an equestrian club with sprawling fields that I’ve seen as many as 20 deer at a time during springtime evenings. Almost every night when I go anywhere I see at least one.

On this particular night, no amount of careful driving, swerving deftly or slamming of breaks managed to save the trip. The deer, while playing the role of an animal content in standing still on his side of the road, didn’t fool me even with the fact that he was tucked away in the opposite lane. There was an instinctive slamming of breaks and dodging to the outside edge of my side of the road at a mere glance of the beast. Apparently in an animal with such an amazingly dense body, the brain matter fails to be quite as capable because it saw a swerving, slowing vehicle coming down the road well away from its position and immediately thought “Wow, cool! I should run in front of that.” And so it did.

The actual event happened remarkably quickly. I would even argue that it happened about as fast as a deer can run, roughly. I freely admit a potentially skewed bias as the observer from inside the car and behind the steering wheel, but this was definitely a large deer. The good news in that is that it wasn’t a fawn, the bad news is that it was both more massive and tougher. Since the back roads have a speed limit of 30 mph and I was honestly going about that when I saw the deer, the impact was destined to not be a horror show. The anti-lock breaks were buzzing away and the car was slowing fast when the deer managed to get in front. I’d estimate 10 to 15 mph was the final impact speed.

Simple physics tell us how much energy a 3200 pound car has at even 10 mph, and how much velocity that translates into in an average 150 pound whitetail deer. The deer flew out of sight above the car and landed to the side of the road in a heap. I believe the translation of energy in an upward direction may have saved both the deer’s life and reduced the damage to my car. Picture shoveling snow for an understanding of how ramps work. My car was still running, now completely stopped, and both headlights were still working. I decided my evening did not need the view of a potentially nasty bit of carnage, so I drove off to complete my drive home.

Once in my own driveway, I walked around my car and thankfully discovered that there was no blood on my car. In its place was a very cracked and damaged driver’s side headlight dome complete with a mangled turn signal light inside, a slightly bent license plate, a bent and banged up hood, and bunches of deer fur wedged in as many places as the front of my car could offer to wedge it into. The good news here is that the damage wasn’t all that bad, and that the pizza had survived the rapid breaking.

The next morning, I drove down that same road on my way to work and was rather happy to see no deer on the side of the road. I firmly believe that while I may have beaten it up pretty badly, and that it may die sooner than was in its original plans, I didn’t kill it on the spot and that makes me pretty happy. Since there aren’t all that many hungry wild animals out in the suburban landscapes of Connecticut, I suspect it wandered off under its own power after the daze wore off.

Wine Making

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For some time now I’ve been a member of an excellent wine club called 4 Seasons that costs me around $750 per year and adds loads of interesting varieties of wine to my wine rack. Each shipment is a case of 12 bottles of wine that includes 2 bottles each of 3 types of white and 3 types of red. They are shipped to me one per season, which is slightly misleading since there are actually 5 seasons in a year through this club. Spring, Summer, Autumn, Holiday, and Winter. Thus, with pretty simple math we can figure out that my wine club is 60 bottles a year at roughly $12.50 a bottle.

Several friends of mine enjoy the hobby of making beer or wine at home. This fact got me seriously thinking. Even as a guy that doesn’t care for beer I have to admit that it sounds like fun. I can imagine an infinite variety of beer types since most of the rules of beer fly out the window when you take control of the entire process. I tend to enjoy activities that are slower but the output is of a finer quality. Beer making and bonsai are prime candidates.

I repeat for good measure that I’m not a beer guy, and also that I am a wine guy. Since you can make both beer and wine at home (with a pretty seriously overlapping list of required equipment for those that are considering it) and I like wine, I saw the direction I wanted to go. After a couple of days of research into prices and lists of equipment I finally felt ready to take the plunge into another new hobby.

Like all hobbies this one has a pretty steep initial purchase curve, but unlike many hobbies, it has the potential to save obscene amounts of money in the long run. My initial purchase of things from my local beer and wine hobby store called Brew & Wine Hobby clocked in at right around $340. That purchase however will produce around 60 bottles of wine. Although I will need a few more bottles and corks when I get to the 2nd kit’s completion, those will only cost me right around $36. So the same math as before leads to the conclusion that for the patient and the passionate the price per bottle is a mere $6.27 and that number continues to drop with each kit I make. With the equipment I now own taken out of the picture, a kit of wine tends to produce 30 bottles at anywhere from around $2.25 to $5.00 per bottle.

The best part is I can now cancel my wine club and that within barely more than 2 shipments from my wine club I will have paid off my purchases. The second best part is the ability to make wines that I would never be able to afford or could afford but have a hard time accepting the price. Beyond that there is control and flexibility in what I make. If I find a kit I like, but have an idea about how it might be better, I can tweak to my heart’s content.

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